76 lines
3.8 KiB
C
76 lines
3.8 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
|
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
|
│ Copyright 2020 Justine Alexandra Roberts Tunney │
|
|
│ │
|
|
│ This program is free software; you can redistribute it and/or modify │
|
|
│ it under the terms of the GNU General Public License as published by │
|
|
│ the Free Software Foundation; version 2 of the License. │
|
|
│ │
|
|
│ This program is distributed in the hope that it will be useful, but │
|
|
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
|
|
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
|
|
│ General Public License for more details. │
|
|
│ │
|
|
│ You should have received a copy of the GNU General Public License │
|
|
│ along with this program; if not, write to the Free Software │
|
|
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
|
|
│ 02110-1301 USA │
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
#include "libc/bits/progn.internal.h"
|
|
#include "libc/bits/safemacros.internal.h"
|
|
#include "libc/mem/mem.h"
|
|
#include "libc/runtime/interruptiblecall.h"
|
|
#include "libc/runtime/runtime.h"
|
|
#include "libc/sysv/consts/sa.h"
|
|
#include "libc/sysv/consts/sig.h"
|
|
|
|
STATIC_YOINK("_init_onntconsoleevent");
|
|
|
|
static struct InterruptibleCall *g_interruptiblecall;
|
|
|
|
wontreturn static void interruptcall(int sig) {
|
|
longjmp(g_interruptiblecall->jb, 1);
|
|
unreachable;
|
|
}
|
|
|
|
/**
|
|
* Calls function that may be cancelled by a signal.
|
|
*
|
|
* @param state is allocated and zero'd by the caller; state→sig and
|
|
* state→sa_new.sa_mask may be set; it may be re-used w/o
|
|
* reinitializing; it may be static or heap memory; it may be stack
|
|
* memory if re-entrant behavior isn't needed
|
|
* @return the value returned by callback or -1 on interrupt; they may
|
|
* be differentiated using the state→returnval filed, which is only
|
|
* modified by this function when callbacks succeed
|
|
*/
|
|
intptr_t interruptiblecall(struct InterruptibleCall *icall,
|
|
intptr_t callback(intptr_t p1, intptr_t p2,
|
|
intptr_t p3, intptr_t p4),
|
|
intptr_t p1, intptr_t p2, intptr_t p3, intptr_t p4) {
|
|
intptr_t rc;
|
|
if (!icall->sig) icall->sig = SIGINT;
|
|
icall->sa_new.sa_handler = interruptcall;
|
|
icall->sa_new.sa_flags |= SA_RESTART | SA_RESETHAND;
|
|
if ((rc = (sigaction)(icall->sig, &icall->sa_new, &icall->sa_old)) != -1) {
|
|
g_interruptiblecall = PROGN((icall->prev = g_interruptiblecall), icall);
|
|
if (!setjmp(icall->jb)) {
|
|
icall->returnval = rc = callback(p1, p2, p3, p4);
|
|
} else {
|
|
rc = -1;
|
|
}
|
|
asm volatile("" ::: "memory");
|
|
struct InterruptibleCall *unwind;
|
|
for (;;) {
|
|
unwind = g_interruptiblecall;
|
|
(sigaction)(unwind->sig, &unwind->sa_old, NULL);
|
|
g_interruptiblecall = unwind->prev;
|
|
if (unwind == icall) break;
|
|
free_s(&unwind);
|
|
}
|
|
icall->prev = NULL;
|
|
}
|
|
return rc;
|
|
}
|